1. Field of the Invention
The present invention relates to solar drying devices and in particular, to a device which may be utilized to remove the moisture content of granular materials, sludge, or the like.
2. Description of the Relevant Art
The use of solar induced convection currents to dry material such as fruits, grains, sludge and the like has been well recognized in the art. These devices include but are not limited to a surface upon which the material to be dried is placed. The sun's rays are focused thereon by means of mirrors, lenses and other reflecting devices to direct the sun's rays onto the material for drying. Inclined planes have also been used to direct the flow of air currents over the material to be dried or, alternatively, the material itself may be placed on an inclined plane so that it may face the sun's rays directly.
Other types of solar collectors use the chimney effect created by the heated air under an inclined glass panel. Generally, these devices heat either air or water which is further circulated to transport the heated matter to another area where the heat is used.
Applications for drying sludge by solar heat are recognized. Generally they require that the sludge be placed into large, open pools where the sun's rays help in the drying process. Additionally, further improvements in this process include raking the sludge to bring the dried portions thereof to the surface to aid in the removal of moisture therefrom. However, all of the known techniques had inherent disadvantages associated therewith.
The present invention overcomes the shortcomings found in the prior art by providing a drying process wherein the material itself is dried on an inclined support means utilizing convection induced evaporation and a materials handling system which includes a means of providing a continuous supply and continuous removal of the material. A novel feature of the present invention is the inclusion of a means of agitating or raking the material while it dries on said support surface to both re-expose wet material and transport the same with the help of gravity from the upper edge of said inclined surface to the bottom edge thereof.